<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Position Test: Test position:sticky element with auto margin in flex container</title>
<link rel="author" title="Ting-Yu Lin" href="mailto:tlin@mozilla.com">
<link rel="author" title="Mozilla" href="https://www.mozilla.org/">
<link rel="help" href="https://drafts.csswg.org/css-position/#staticpos-rect">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1488080">
<link rel="match" href="../../reference/ref-filled-green-100px-square.xht">
<meta name="assert" content="This test verifies that a position:sticky element aligning with 'auto' margin still honors the sticky positioning.">

<style>
#container{
  width: 100px;
  height: 100px;
  overflow: hidden;
  background: red;
}
.flex {
  display: flex;
  flex-direction: column;
  height: 500px;
}
.child {
  width: 100px;
  height: 100px;
  background: green;
  position: sticky;
  margin-top: auto;
  bottom: 0;
}
</style>

<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
<div id="container">
  <div class="flex">
    <div class="child"></div>
  </div>
</div>
